1. Field of the Invention
The present invention relates to the structure for high-frequency oscillators, more particularly, to an oscillator structure having a master circuit board for forming a plurality of oscillator units, each being tested directly without being detached from the master circuit board.
2. Description of Related Art
The high-frequency oscillator, such as a microwave or voltage control oscillator, is usually manufactured as a small piece of a circuit board and covered by a metal mask to avoid parasitic oscillation and interference resulting from the high oscillating frequency. In mass production, a plurality of isolated oscillator units are formed on a large master circuit board, which is then cut to obtain each individual oscillator on a small piece of circuit board. As shown in FIG. 4, a plurality of isolated oscillator units (55) are formed on a master circuit board (50). Two U-shaped apertures (51,52) are defined by piercing the master circuit board (50) around the boundary of each oscillator unit (55) whereby each oscillator unit (55) is only supported by two thin tie bars (53, 54). Afterwards, the tie bars (53,54) can be broken manually to detach each oscillator unit (55) for testing.
Referring to FIG. 5A, another conventional master circuit board (60) for manufacturing high-frequency oscillators is shown. A plurality of identical oscillator units (61), arranged in a matrix form, are formed on the master circuit board (60). Each one of the plurality of oscillator units (61) is isolated by a plurality of intersected vertical and horizontal etched grooves (14) defined by using an etching knife device with a V-shaped knife edge. FIG. 5B is a cross sectional view of the master circuit board (60), which further shows that the etched grooves (14) are defined in both faces of the master circuit board so that two adjacent oscillator units (61) are loosely tied together. Afterwards, the master circuit board (60) can be easily broken along the etched grooves (14) to obtain the plurality of oscillator units (61) for testing.
The test to the oscillator units (55,61) formed on a small piece of circuit board and detached form the master circuit board (50,60) as described above is complicated because all the oscillator units (51,61) have to be tested one by one, and each test is inconvenient to implement. Each oscillator unit (55, 61) has to be tested in a test seat (70) specifically configured to hold an oscillator unit (90), as shown in FIG. 6. The test seat (70) has a position slot (71) defined therein to hold the to-be-tested oscillator unit (90). Each side of the test seat (70) defines a pass slot (72) communicated with the position slot (71) for positioning cables and a signal connector (74). Furthermore, a thin circuit board (80) having a shape fitted to the position slot (71) and pass slots (72) has to be provided to stick into the test seat (70). The thin circuit board (80) has several copper foil contacts (82) and a copper foil ground (81) formed on the surface. The external terminal of each copper foil (81,82) is used to electrically connect with power lines, signal wires, or the signal connector (74). The internal terminal of each copper foil (81,82) is used to electrically connect to the oscillator unit (90) under test thereby supplying power and transmitting signals to the oscillator unit (90) to obtain output signals from the signal connector (74) to perform tests. In addition, when a test is to be performed, a rubber block (73) has to be inserted into the position slot (71) after the oscillator unit (90) is positioned therein thereby forcing the oscillator unit (90) to make and maintain secure contact with the thin circuit board (80) to ensure effective electrical contact. Accordingly, it is obvious that the test is inconvenient because a dedicated test seat (70) has to be made and each to-be-tested oscillator unit (90) has to be positioned in and taken away from the test seat (70) manually. Therefore, there is a need to provide a new and improved oscillator structure to remove the inconvenience and complexity in testing.